Today, we're discussing about two major things, the alleged OverSky Jailbreak developed by Min(Spark) Zheng but still not public, and the fact that Apple closed the signature Window for iOS 9.3.3 and iOS 9.3.2 and released iOS 9.3.5 today.
Min Zheng posted a video in which he was demoing cydia installation on iOS 9.3.4 in a similar method used by Pangu for 9.3.3. I say similar, because he couldn't have used the same exploits due to the fact that they were patched by Apple in iOS 9.3.4. As for now there is no word about any release of this tool; some people believe that Min Zheng will sell the exploits for either a bounty or to Apple, but I guess we'll hear about soon.
Min also posted a video called "Flying Jailbreak" which targeted iOS 9.2.1 back in June, but it was not followed by any Release.
In terms of releases, Apple decided to stop signing the iOS 9.3.2 after a month of additional signing (never happened before). They also stopped iOS 9.3.3 who was also signed for 3 weeks more than their normal timetables. In fact, iOS 9.3.4 will most likely be deprecated soon as iOS 9.3.5 fixes 2 important kernel vulnerabilities and one in the WebKit which could have rendered a Jailbreak.
You should NOT update to iOS 9.3.4 or iOS 9.3.5!
OverSky Jailbreak Demo: https://www.youtube.com/watch?v=GsPmG8-kMK8
iOS 9.3.5 Contents: https://support.apple.com/en-us/HT207107